Function dispatchAction

src/component/brush/visualEncoding.ts:241–284

(
    api: ExtensionAPI,
    throttleType: throttleUtil.ThrottleType,
    throttleDelay: number,
    brushSelected: BrushSelectedItem[],
    payload: Payload
)

};

function dispatchAction(
    api: ExtensionAPI,
    throttleType: throttleUtil.ThrottleType,
    throttleDelay: number,
    brushSelected: BrushSelectedItem[],
    payload: Payload
): void {
    // This event will not be triggered when `setOption`, otherwise dead lock may
    // triggered when do `setOption` in event listener, which we do not find
    // satisfactory way to solve yet. Some considered resolutions:
    // (a) Diff with previous selected data ant only trigger event when changed.
    // But store previous data and diff precisely (i.e., not only by dataIndex, but
    // also detect value changes in selected data) might bring complexity or fragility.
    // (b) Use special param like `silent` to suppress event triggering.
    // But such kind of volatile param may be weird in `setOption`.
    if (!payload) {
        return;
    }

    // FIXME: [INCONSISTENCY_OF_BRUSH_SELECTED_EVENT_IN_UPDATE_TRANSFORM]
    // If any series declared in ec option does not support `updateTransform`, `updateTransform` will
    // dirty the pipeline (see `echarts.ts`), thereby `reset` of `brush/visualEncoding.ts` being called,
    // and then 'brushselected' event is triggered here.
    // If all series declared in ec option support `updateTransform` and return no 'update', the pipeline
    // will not be dirty, consequently `reset` is not called and 'brushselected' event is not triggered.
    // This inconsistency is unreasonable and error-prone.
    // Theoretically, 'brushselected' should always be triggered, since the "brush covers" may stay at its
    // original place even when roaming (depending on settings). But we should not use `dirtyOnOverallProgress`
    // in this visual task, otherwise all pipelines will be blocked and progressive rendering is broken.
    // Therefore, the mechanism of `updateTranform` and `updateVisual` needs to review and refactor.

    const zr = api.getZr() as BrushGlobalDispatcher;
    if (zr[DISPATCH_FLAG]) {
        return;
    }

    if (!zr[DISPATCH_METHOD]) {
        zr[DISPATCH_METHOD] = doDispatch;
    }

    const fn = throttleUtil.createOrUpdate(zr, DISPATCH_METHOD, throttleDelay, throttleType);

    fn(api, brushSelected);
}

function doDispatch(api: ExtensionAPI, brushSelected: BrushSelectedItem[]): void {
    if (!api.isDisposed()) {